How Does Your Garden Grow? Learning to grow tropicals

Published: Saturday, Aug. 24, 2013 5:30 a.m. CST

Caption

(Provided photo)

Mandeville vine in bloom.

By BARBARA LINDHOLM | DeKalb County Master Gardener

Is it possible to successfully grow tropical plants in the Midwest? Absolutely! Tropical plants are enjoying a current popularity boom as they offer both summer drama in the garden and indoor displays for the winter months.

It is definitely possible to create the tropics in your own backyard. What elements combine to form a lush, tropical garden design? The three most important components of this design all begin with the letter F. They are foliage, flowers and form.

Dramatic foliage plants form both the base and the focal points of a tropical garden. Plants with small- to medium-size leaves are used for the front and the middle. Multi-colored coleus and crotons, small forms of cannas and hibiscus are good plants for the front and center of the garden. Attention grabbing foliage plants for the back of the garden include large leafed elephant ears, 6-foot tropical cannas, ostrich ferns and, if you can find it, gunnera.

Vibrant color will appear in the garden palette with the addition of the flowers. Some recommended flowers for the tropical design are hibiscus, cannas and Bird of Paradise. Additional flower accents can be added by planting colorful annuals such as New Guinea impatiens and fuchsias.

A variety of forms and textures are what ultimately creates the overall tropical look. The differing appearance and size of plants such as tall cannas and Bird of Paradise combined with the more delicate ostrich ferns displayed with large-leafed elephant ears and even large hostas such as “Sum and Substance” played against the smaller forms of coleus and crotons, all blend together for the tropical garden design.

If you would like to take your tropical garden up a notch to almost jungle, you can add vines as great accent pieces showing good foliage, flowers and form. Some vines that do well in a tropical setting include purple hyacinth bean, orange clockvine, yellow trumpet creeper and the very dramatic, large flowered red or pink mandeville vine.

And now it is time for a reality check. Tropical plants are the opposite of native plants. They will need special care in our area.

Many tropical plants will grow in full sun while others prefer partial shade. You will need to research individual plants for their best growing exposure. Tropicals are heavy feeders requiring soil that remains uniformly moist. They also need to be fertilized every two weeks with a nitrogen rich fertilizer. Remember they are trying to produce those gigantic leaves.

Tropical plants will need to be moved back indoors when night temperatures dip below 50 degrees as they are very frost sensitive. Potted tropicals will be easier to transition from outdoor back to indoor plants. During the summer, potted plants can be displayed above ground or sunk in the ground for a more natural appearance.

The good news about tropicals is that they actually thrive outdoors in our Midwest summer heat and humidity. Another good feature is that when our annuals and perennials are waning in mid-summer and early fall, tropicals are happy to take over as this is the very best time of year for them.

Garfield Park Conservatory in Chicago has a great display of plants in their Palm House structure. You can view it to better understand the concept of tropical garden design by visiting the conservatory or by checking it out on their website.

Tropical gardening is not new. It was extremely popular in Victorian times. Tropicals do require special care, but their ability to transition from summering plants to winter plants gives gardeners the opportunity to enjoy them all year long.

• The Master Gardeners are available to answer questions from 9 a.m. to noon Monday through Friday at the University of Illinois Extension DeKalb County office located in the Farm Bureau Center for Agriculture, 1350 W. Prairie Drive in Sycamore. Call 815-758-8194 or email DeKalb_mg@extension.uiuc.edu. Walk-ins are welcome.